Mercurial > repos > blastem
annotate oscilloscope.c @ 2275:e27ab5f4bfe3
Fix off by one in oscilloscope rendering
| author | Michael Pavone <pavone@retrodev.com> |
|---|---|
| date | Mon, 02 Jan 2023 11:36:16 -0800 |
| parents | d220305e81b9 |
| children | d30ea441b92e |
| rev | line source |
|---|---|
| 2245 | 1 #include "oscilloscope.h" |
| 2 #include "render.h" | |
| 3 #include "blastem.h" | |
| 4 | |
| 5 #define INVALID_TRIGGER 0xFFFFFFFF | |
| 6 #define WIDTH 1280 | |
| 7 #define HEIGHT 720 | |
| 8 | |
| 9 static void scope_window_close(uint8_t which) | |
| 10 { | |
| 11 if (current_system && current_system->toggle_debug_view) { | |
| 12 current_system->toggle_debug_view(current_system, DEBUG_OSCILLOSCOPE); | |
| 13 } | |
| 14 } | |
| 15 | |
| 16 oscilloscope *create_oscilloscope() | |
| 17 { | |
| 18 oscilloscope *scope = calloc(1, sizeof(oscilloscope)); | |
| 19 scope->channel_storage = 4; | |
| 20 scope->channels = calloc(scope->channel_storage, sizeof(scope_channel)); | |
| 21 scope->window = render_create_window("Oscilloscope", WIDTH, HEIGHT, scope_window_close); | |
| 22 return scope; | |
| 23 } | |
| 24 uint8_t scope_add_channel(oscilloscope *scope, const char *name, uint32_t sample_rate) | |
| 25 { | |
| 26 if (scope->num_channels == scope->channel_storage) { | |
| 27 scope->channel_storage *= 2; | |
| 28 scope->channels = realloc(scope->channels, scope->channel_storage * sizeof(scope_channel)); | |
| 29 } | |
| 30 uint8_t channel = scope->num_channels++; | |
| 31 scope_channel *chan = scope->channels + channel; | |
| 32 chan->name = name; | |
| 33 chan->period = sample_rate / 30; | |
| 34 chan->next_sample = 0; | |
| 35 chan->samples = calloc(chan->period, sizeof(int16_t)); | |
| 36 chan->last_trigger = INVALID_TRIGGER; | |
| 37 chan->cur_trigger = INVALID_TRIGGER; | |
| 38 return channel; | |
| 39 } | |
| 40 void scope_add_sample(oscilloscope *scope, uint8_t channel, int16_t value, uint8_t trigger) | |
| 41 { | |
| 42 if (channel >= scope->num_channels) { | |
| 43 return; | |
| 44 } | |
| 45 scope_channel *chan = scope->channels + channel; | |
| 46 if (trigger) { | |
| 47 chan->cur_trigger = chan->next_sample; | |
| 48 } | |
| 49 chan->samples[chan->next_sample++] = value; | |
| 50 if (chan->next_sample == chan->period) { | |
| 51 chan->next_sample = 0; | |
| 52 } | |
| 53 } | |
| 54 void scope_render(oscilloscope *scope) | |
| 55 { | |
| 56 int pitch; | |
| 57 uint32_t *fb = render_get_framebuffer(scope->window, &pitch); | |
| 58 memset(fb, 0, HEIGHT * pitch); | |
| 59 pitch /= sizeof(uint32_t); | |
| 60 int offset = 0; | |
| 61 int column_width = WIDTH/3; | |
| 62 int width = column_width * 3; | |
| 63 int row_height = HEIGHT / ((scope->num_channels + 2) / 3); | |
| 64 float value_scale = (float)row_height / 20000.0f; | |
| 65 uint32_t *cur_line = fb; | |
| 66 for (uint8_t i = 0; i < scope->num_channels; i++) | |
| 67 { | |
| 68 float samples_per_pixel = (float)scope->channels[i].period / (float)(2*column_width); | |
| 69 uint32_t start = scope->channels[i].last_trigger; | |
| 70 if (start == INVALID_TRIGGER) { | |
| 71 if (scope->channels[i].next_sample >= scope->channels[i].period / 2) { | |
| 72 start = scope->channels[i].next_sample - scope->channels[i].period / 2; | |
| 73 } else { | |
| 74 start = scope->channels[i].period - (scope->channels[i].period /2 - scope->channels[i].next_sample); | |
| 75 } | |
| 76 } | |
| 77 scope->channels[i].last_trigger = scope->channels[i].cur_trigger; | |
| 78 scope->channels[i].cur_trigger = INVALID_TRIGGER; | |
| 79 float cur_sample = start; | |
| 80 int last_y = -1; | |
| 81 for (int x = offset; x < offset + column_width; x++) | |
| 82 { | |
| 83 //TODO: bresenham | |
| 84 //TODO: at least linear filtering | |
| 85 int16_t sample = scope->channels[i].samples[(int)(cur_sample + 0.5f)]; | |
| 86 int y = (float)sample * value_scale + 0.5f; | |
|
2275
e27ab5f4bfe3
Fix off by one in oscilloscope rendering
Michael Pavone <pavone@retrodev.com>
parents:
2245
diff
changeset
|
87 if (y > row_height / 2 - 1) { |
|
e27ab5f4bfe3
Fix off by one in oscilloscope rendering
Michael Pavone <pavone@retrodev.com>
parents:
2245
diff
changeset
|
88 y = row_height / 2 - 1; |
| 2245 | 89 } else if (y < -(row_height / 2)) { |
| 90 y = -(row_height / 2); | |
| 91 } | |
| 92 y += row_height / 2; | |
| 93 if (last_y >= 0) { | |
| 94 int delta = last_y > y ? -1 : 1; | |
| 95 while (last_y != y) | |
| 96 { | |
| 97 cur_line[last_y * pitch + x ] = 0xFFFFFFFF; | |
| 98 last_y += delta; | |
| 99 } | |
| 100 } else { | |
| 101 last_y = y; | |
| 102 } | |
| 103 cur_line[y * pitch + x ] = 0xFFFFFFFF; | |
| 104 cur_sample += samples_per_pixel; | |
| 105 if (cur_sample + 0.5f >= scope->channels[i].period) { | |
| 106 cur_sample -= scope->channels[i].period; | |
| 107 } | |
| 108 } | |
|
2275
e27ab5f4bfe3
Fix off by one in oscilloscope rendering
Michael Pavone <pavone@retrodev.com>
parents:
2245
diff
changeset
|
109 |
| 2245 | 110 offset += column_width; |
| 111 if (offset >= width) { | |
| 112 offset = 0; | |
| 113 cur_line += pitch * row_height; | |
| 114 } | |
| 115 } | |
|
2275
e27ab5f4bfe3
Fix off by one in oscilloscope rendering
Michael Pavone <pavone@retrodev.com>
parents:
2245
diff
changeset
|
116 |
|
e27ab5f4bfe3
Fix off by one in oscilloscope rendering
Michael Pavone <pavone@retrodev.com>
parents:
2245
diff
changeset
|
117 |
| 2245 | 118 render_framebuffer_updated(scope->window, WIDTH); |
| 119 } | |
| 120 | |
| 121 void scope_close(oscilloscope *scope) | |
| 122 { | |
| 123 render_destroy_window(scope->window); | |
| 124 for (uint8_t i = 0; i < scope->num_channels; i++) | |
| 125 { | |
| 126 free(scope->channels[i].samples); | |
| 127 } | |
| 128 free(scope->channels); | |
| 129 free(scope); | |
| 130 } |