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annotate src/vdp.c @ 26:083347ccd508

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Implemented vblank interrupts and fixed a bug in exception vector address calculation
author Michael Pavone <pavone@retrodev.com>
date Fri, 01 Apr 2016 21:34:38 -0700
parents a085f17b79e9
children 6e7bfe83d2b0
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8
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1 #include <stdint.h>
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2 #include <string.h>
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3 #include <stdio.h>
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4 #include "vdp.h"
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5 #include "system.h"
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6
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7 void vdp_init(vdp *context, uint32_t clock_div)
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8 {
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9 memset(context, 0, sizeof(vdp));
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10 //clock div specifies the pixel clock divider
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11 //but our emulation step is half that fast
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12 context->clock_inc = clock_div*2;
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13 context->drawbuffer = context->linebuffers;
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14 context->readbuffer = context->linebuffers+320;
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15 }
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16
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17 void vdp_run(vdp *context, uint32_t target)
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18 {
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19 while (context->cycles < target)
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20 {
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21 context->hcounter+=2;
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22 if (context->hcounter == 416) {
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23 context->hcounter = 0;
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24 context->vcounter++;
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25 if (context->vcounter == 262) {
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26 context->vcounter = 0;
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27 }
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28 }
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29 context->status &= ~(VDP_STATUS_VRAM|VDP_STATUS_SRAM);
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30 //Render to linebuffer
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31 if ((context->status & VDP_STATUS_ENABLED) && context->vcounter > 15 && context->vcounter < 240 && context->hcounter < 406) {
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32 if (context->hcounter < 246) {
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33 context->status |= VDP_STATUS_VRAM;
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34 if (!context->hcounter) {
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35 //flip linebuffers
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36 if (context->drawbuffer == context->linebuffers) {
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37 context->drawbuffer = context->linebuffers + 328;
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38 context->readbuffer = context->linebuffers;
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39 } else {
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40 context->drawbuffer = context->linebuffers;
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41 context->readbuffer = context->linebuffers + 328;
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42 }
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43 context->draw_dest = 0;
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44 //enable sprite scanning
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45 context->status |= VDP_STATUS_SPRITE_SCAN;
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46 context->current_draw = 0;
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47 }
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48 if (context->draw_counter) {
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49 context->draw_counter--;
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50 uint16_t pixels = context->vram[context->draw_source++];
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51 for (int i = context->hflip ? 0 : 12; i >= 0 && i < 16; i+= context->hflip ? 4 : -4)
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52 {
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53 uint8_t pixel = ((pixels >> i) & 0xF) | context->palpriority;
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54 context->drawbuffer[context->draw_dest ^ (context->hflip << 2)] = pixel;
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55 context->draw_dest++;
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56 }
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57 } else {
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58 //00VV VVVV VVHH HHHH
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59 uint16_t vpos = (context->vscroll & 0x7FF) + context->vcounter - 16;
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60 uint16_t vmask = (context->vscroll >> 2) & 0x3E00;
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61 uint16_t vcoarse = (vpos << 3) & 0x3FC0;
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62 uint16_t vfine = vpos & 7;
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63 uint16_t hcoarse = ((context->hscroll >> 3) + context->hcounter/6) & 0x3F;
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64 uint16_t tableaddress = hcoarse | (vcoarse & ~vmask) | ((context->vscroll << 3) & vmask);
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65 //printf("VCounter: %X, VScroll: %X, HCounter: %X, Table: %X\n", context->vcounter, context->vscroll, context->hcounter, tableaddress);
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66 uint16_t entry = context->vram[tableaddress];
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67 context->draw_source = (entry & 0x3FF) * 16;
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68 if (entry & 0x1000) {
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69 context->draw_source += 14 - vfine * 2;
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70 } else {
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71 context->draw_source += vfine * 2;
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72 }
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73 context->palpriority = entry >> 9 & 0x70;
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74 context->draw_counter = 2;
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75 context->hflip = (entry & 0x800) != 0;
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76 }
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77 if (context->status & VDP_STATUS_SPRITE_SCAN) {
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78 context->status |= VDP_STATUS_SRAM;
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79 uint16_t pos = context->sram[context->hcounter];
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80 uint16_t y = pos & 0xFF;
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81 uint16_t x = pos >> 8;
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82 uint16_t atts = context->sram[context->hcounter+1];
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83 x |= atts << 2 & 0x100;
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84 if (x | y) {
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85 uint16_t size = atts & 0x400 ? 16 : 8;
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86 if (context->vcounter >= y && context->vcounter < y + size) {
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87 uint16_t address = (atts & 0x3F) * 16;
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88 if (atts & 0x1000) {
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89 address += (size-1) * 2 - (context->vcounter - y) * 2;
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90 } else {
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91 address += (context->vcounter - y) * 2;
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92 }
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93 context->sprite_draws[context->current_draw].source = address;
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94 context->sprite_draws[context->current_draw].x = x;
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95 context->sprite_draws[context->current_draw].hflip = (atts & 0x800) != 0;
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96 context->sprite_draws[context->current_draw].palpriority = 0x80 | (atts >> 9 & 0x50);
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97 context->current_draw++;
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98 if (size == 16) {
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99 context->sprite_draws[context->current_draw].source = address + 32;
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100 context->sprite_draws[context->current_draw].x = x + 8;
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101 context->sprite_draws[context->current_draw].hflip = (atts & 0x800) != 0;
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102 context->sprite_draws[context->current_draw].palpriority = 0x80 | (atts >> 9 & 0x50);
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103 if (context->sprite_draws[context->current_draw].hflip) {
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104 context->sprite_draws[context->current_draw].x -= 8;
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105 context->sprite_draws[context->current_draw-1].x += 8;
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106 }
22
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107 }
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108 context->current_draw++;
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109 if (context->current_draw == 40) {
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110 //no more rendering capacity
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111 context->status &= ~VDP_STATUS_SPRITE_SCAN;
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112 context->current_draw = 0;
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113 }
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114 }
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115 } else {
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116 //hit sprite list terminator
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117 context->status &= ~VDP_STATUS_SPRITE_SCAN;
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118 context->current_draw = 0;
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119 }
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120 }
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121 } else {
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122 sprite_draw *draw = context->sprite_draws + (context->current_draw >> 1);
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123 if (draw->palpriority) {
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124 context->status |= VDP_STATUS_VRAM;
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125 uint16_t pixels = context->vram[draw->source + (context->current_draw & 1)];
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126 uint16_t x = draw->x - 16 + (context->hscroll & 7);
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127 for (int i = draw->hflip ? 0 : 12; i >= 0 && i < 16; i+= draw->hflip ? 4 : -4, x++)
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128 {
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129 uint8_t pixel = (pixels >> i) & 0xF;
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130 if (pixel && x < 328 && ((draw->palpriority & 0x40) || !(context->drawbuffer[x] & 0x40))) {
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131 context->drawbuffer[x ^ (draw->hflip << 2)] = pixel | draw->palpriority;
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132 }
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133 }
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134 if (context->current_draw & 1) {
407725d9a02f Implemented sprite drawing. Added small sprite example.
Michael Pavone <pavone@retrodev.com>
parents: 21
diff changeset
135 draw->palpriority = 0;
407725d9a02f Implemented sprite drawing. Added small sprite example.
Michael Pavone <pavone@retrodev.com>
parents: 21
diff changeset
136 } else {
407725d9a02f Implemented sprite drawing. Added small sprite example.
Michael Pavone <pavone@retrodev.com>
parents: 21
diff changeset
137 draw->x += 4;
407725d9a02f Implemented sprite drawing. Added small sprite example.
Michael Pavone <pavone@retrodev.com>
parents: 21
diff changeset
138 }
407725d9a02f Implemented sprite drawing. Added small sprite example.
Michael Pavone <pavone@retrodev.com>
parents: 21
diff changeset
139 }
407725d9a02f Implemented sprite drawing. Added small sprite example.
Michael Pavone <pavone@retrodev.com>
parents: 21
diff changeset
140 context->current_draw++;
19
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
141 }
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
142 }
11
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
143 //Draw to framebuffer
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
144 if (context->vcounter > 8 && context->vcounter < 249 && context->hcounter < 320) {
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
145 if (!context->hcounter && context->vcounter == 9) {
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
146 context->framebuffer = system_get_framebuffer(&context->pitch);
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
147 //pitch is in terms of bytes, but we want it in terms of pixels
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
148 context->pitch /= sizeof(uint16_t);
26
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
149 //clear pending interrupt flag since VBlank is over
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
150 context->status &= ~VDP_STATUS_PENDING_VINT;
11
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
151 }
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
152 uint16_t *dest = context->framebuffer + (context->vcounter - 9) * context->pitch + context->hcounter;
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
153 if (context->status & VDP_STATUS_ENABLED && context->vcounter > 16 && context->vcounter < 241) {
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
154 *dest = context->cram[0x3F & context->readbuffer[context->hcounter]];
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
155 dest++;
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
156 *dest = context->cram[0x3F & context->readbuffer[context->hcounter+1]];
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
157 } else {
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
158 //Display is disabled or we're in the border area, draw the background color
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
159 *dest = *context->cram;
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
160 dest++;
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
161 *dest = *context->cram;
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
162 }
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
163 } else if(!context->hcounter && context->vcounter == 249) {
26
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
164 if (context->status & VDP_STATUS_ENABLED) {
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
165 context->status |= VDP_STATUS_PENDING_VINT;
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
166 }
11
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
167 system_framebuffer_updated();
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
168 context->framebuffer = NULL;
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
169 }
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
170 //Handle the FIFO
8
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
171 if (context->status & VDP_STATUS_FIFO) {
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
172 switch (context->fifo_dest)
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
173 {
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
174 case FIFO_DEST_VRAM:
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
175 if (!(context->status & VDP_STATUS_VRAM)) {
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
176 context->vram[context->dest_offset++] = context->fifo;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
177 context->dest_offset &= sizeof(context->vram)/2-1;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
178 context->status &= ~VDP_STATUS_FIFO;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
179 }
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
180 break;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
181 case FIFO_DEST_SRAM:
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
182 if (!(context->status & VDP_STATUS_SRAM)) {
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
183 context->sram[context->dest_offset++] = context->fifo;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
184 context->dest_offset &= sizeof(context->sram)/2-1;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
185 context->status &= ~VDP_STATUS_FIFO;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
186 }
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
187 break;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
188 case FIFO_DEST_CRAM:
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
189 context->cram[context->dest_offset++] = context->fifo;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
190 context->dest_offset &= sizeof(context->cram)/2-1;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
191 context->status &= ~VDP_STATUS_FIFO;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
192 break;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
193 }
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
194 }
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
195 context->cycles += context->clock_inc;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
196 }
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
197 }
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
198 void vdp_write_address(vdp *context, uint16_t value)
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
199 {
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
200 context->status &= ~VDP_STATUS_FIFO;
11
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
201 if (!(value & 0x8000)) {
8
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
202 context->fifo_dest = FIFO_DEST_VRAM;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
203 context->dest_offset = (value & (sizeof(context->vram) -1))/2;
11
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
204 } else if ((value & 0xFF00) == 0xFE00) {
8
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
205 context->fifo_dest = FIFO_DEST_SRAM;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
206 context->dest_offset = (value & (sizeof(context->sram) -1))/2;
11
04d8efe7a1f0 Initial stab at video output and background color rendering. Fixed address decoding in address port write handler.
Michael Pavone <pavone@retrodev.com>
parents: 8
diff changeset
207 } else if ((value & 0xFF00) == 0xFF00) {
8
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
208 context->fifo_dest = FIFO_DEST_CRAM;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
209 context->dest_offset = (value & (sizeof(context->cram) -1))/2;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
210 }
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
211 }
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
212
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
213 void vdp_write_data(vdp *context, uint16_t value)
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
214 {
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
215 context->fifo = value;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
216 context->status |= VDP_STATUS_FIFO;
5176efdda5ae Initial work on VDP emulation
Michael Pavone <pavone@retrodev.com>
parents:
diff changeset
217 }
19
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
218
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
219 void vdp_write_hscroll(vdp *context, uint16_t value)
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
220 {
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
221 context->hscroll = value & 0x1FF;
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
222 if (value & 0x8000) {
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
223 context->status |= VDP_STATUS_ENABLED;
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
224 } else {
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
225 context->status &= ~VDP_STATUS_ENABLED;
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
226 }
04fc17376999 Sort of working tile rendering and tile test ROM
Michael Pavone <pavone@retrodev.com>
parents: 11
diff changeset
227 }
26
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
228
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
229 uint32_t vdp_next_interrupt(vdp *context)
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
230 {
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
231 if (context->status & VDP_STATUS_PENDING_VINT) {
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
232 return 0;
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
233 } else if (context->status & VDP_STATUS_ENABLED) {
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
234 uint32_t next_line = context->vcounter + 1;
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
235 uint32_t next_line_cyc = context->cycles + ((416 - context->hcounter) >> 1) * context->clock_inc;
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
236 if (context->vcounter < 249) {
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
237 return next_line_cyc + (249 - next_line) * 832;
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
238 } else {
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
239 return next_line_cyc + (249 + 262 - next_line) * 832;
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
240 }
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
241 } else {
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
242 return 0xFFFFFFFF;
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
243 }
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
244 }
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
245
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
246 void vdp_ack_interrupt(vdp *context)
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
247 {
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
248 context->status &= ~VDP_STATUS_PENDING_VINT;
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
249 }
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
250
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
251 uint8_t vdp_interrupt_pending(vdp *context)
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
252 {
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
253 return (context->status & VDP_STATUS_PENDING_VINT) != 0;
083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation
Michael Pavone <pavone@retrodev.com>
parents: 23
diff changeset
254 }