new sample: sbuftex-sapp

sapp/CMakeLists.txt

@@ -126,6 +126,20 @@ fips_begin_app(texcube-sapp-ui windowed)
     target_compile_definitions(texcube-sapp-ui PRIVATE USE_DBG_UI)
 fips_end_app()
 
+fips_ide_group(Samples)
+fips_begin_app(sbuftex-sapp windowed)
+    fips_files(sbuftex-sapp.c)
+    sokol_shader_debuggable(sbuftex-sapp.glsl ${slang})
+    fips_deps(sokol)
+fips_end_app()
+fips_ide_group(SamplesWithDebugUI)
+fips_begin_app(sbuftex-sapp-ui windowed)
+    fips_files(sbuftex-sapp.c)
+    sokol_shader(sbuftex-sapp.glsl ${slang})
+    fips_deps(sokol dbgui)
+    target_compile_definitions(sbuftex-sapp-ui PRIVATE USE_DBG_UI)
+fips_end_app()
+
 fips_ide_group(Samples)
 fips_begin_app(offscreen-sapp windowed)
     fips_files(offscreen-sapp.c)

sapp/sbuftex-sapp.c

@@ -0,0 +1,200 @@
+//------------------------------------------------------------------------------
+//  sbuftex-sapp.c
+//
+//  Test whether binding texture and storage buffers to the same shader stage
+//  works.
+//
+//  The vertex shader pulls vertices and a color palette index from a storage
+//  buffer. The color palette index is passed to the fragment shader.
+//
+//  In the fragment shader, a color palette lookup is done via a storage buffer,
+//  and the resulting color is modulated by a texture.
+//------------------------------------------------------------------------------
+#include "sokol_app.h"
+#include "sokol_gfx.h"
+#include "sokol_log.h"
+#include "sokol_glue.h"
+#define HANDMADE_MATH_IMPLEMENTATION
+#define HANDMADE_MATH_NO_SSE
+#include "HandmadeMath.h"
+#include "dbgui/dbgui.h"
+#include "sbuftex-sapp.glsl.h"
+
+static struct {
+    float rx, ry;
+    sg_pass_action pass_action;
+    sg_pipeline pip;
+    sg_bindings bind;
+} state;
+
+static vs_params_t make_vs_params(void);
+
+static void init(void) {
+    sg_setup(&(sg_desc){
+        .environment = sglue_environment(),
+        .logger.func = slog_func,
+    });
+    __dbgui_setup(sapp_sample_count());
+
+    // if no storage buffers supported, just clear the screen to red
+    if (!sg_query_features().storage_buffer) {
+        state.pass_action = (sg_pass_action){
+            .colors[0] = { .load_action = SG_LOADACTION_CLEAR, .clear_value = { 1.0f, 0.0f, 0.0f, 1.0f } },
+        };
+        return;
+    }
+    // otherwise clear to a regular color
+    state.pass_action = (sg_pass_action){
+        .colors[0] = { .load_action = SG_LOADACTION_CLEAR, .clear_value = { 0.5f, 0.75f, 0.25f } },
+    };
+
+    // a storage buffer with cube vertices
+    sb_vertex_t vertices[] = {
+        { .pos = { -1.0f, -1.0f, -1.0f },  .idx = 0, .uv = { 0.0f, 0.0f } },
+        { .pos = {  1.0f, -1.0f, -1.0f },  .idx = 0, .uv = { 1.0f, 0.0f } },
+        { .pos = {  1.0f,  1.0f, -1.0f },  .idx = 0, .uv = { 1.0f, 1.0f } },
+        { .pos = { -1.0f,  1.0f, -1.0f },  .idx = 0, .uv = { 0.0f, 1.0f } },
+
+        { .pos = { -1.0f, -1.0f,  1.0f },  .idx = 1, .uv = { 0.0f, 0.0f } },
+        { .pos = {  1.0f, -1.0f,  1.0f },  .idx = 1, .uv = { 1.0f, 0.0f } },
+        { .pos = {  1.0f,  1.0f,  1.0f },  .idx = 1, .uv = { 1.0f, 1.0f } },
+        { .pos = { -1.0f,  1.0f,  1.0f },  .idx = 1, .uv = { 0.0f, 1.0f } },
+
+        { .pos = { -1.0f, -1.0f, -1.0f },  .idx = 2, .uv = { 0.0f, 0.0f } },
+        { .pos = { -1.0f,  1.0f, -1.0f },  .idx = 2, .uv = { 1.0f, 0.0f } },
+        { .pos = { -1.0f,  1.0f,  1.0f },  .idx = 2, .uv = { 1.0f, 1.0f } },
+        { .pos = { -1.0f, -1.0f,  1.0f },  .idx = 2, .uv = { 0.0f, 1.0f } },
+
+        { .pos = {  1.0f, -1.0f, -1.0f },  .idx = 3, .uv = { 0.0f, 0.0f } },
+        { .pos = {  1.0f,  1.0f, -1.0f },  .idx = 3, .uv = { 1.0f, 0.0f } },
+        { .pos = {  1.0f,  1.0f,  1.0f },  .idx = 3, .uv = { 1.0f, 1.0f } },
+        { .pos = {  1.0f, -1.0f,  1.0f },  .idx = 3, .uv = { 0.0f, 1.0f } },
+
+        { .pos = { -1.0f, -1.0f, -1.0f },  .idx = 4, .uv = { 0.0f, 0.0f } },
+        { .pos = { -1.0f, -1.0f,  1.0f },  .idx = 4, .uv = { 1.0f, 0.0f } },
+        { .pos = {  1.0f, -1.0f,  1.0f },  .idx = 4, .uv = { 1.0f, 1.0f } },
+        { .pos = {  1.0f, -1.0f, -1.0f },  .idx = 4, .uv = { 0.0f, 1.0f } },
+
+        { .pos = { -1.0f,  1.0f, -1.0f },  .idx = 5, .uv = { 0.0f, 0.0f } },
+        { .pos = { -1.0f,  1.0f,  1.0f },  .idx = 5, .uv = { 1.0f, 0.0f } },
+        { .pos = {  1.0f,  1.0f,  1.0f },  .idx = 5, .uv = { 1.0f, 1.0f } },
+        { .pos = {  1.0f,  1.0f, -1.0f },  .idx = 5, .uv = { 0.0f, 1.0f } },
+    };
+    state.bind.vs.storage_buffers[SLOT_vertices] = sg_make_buffer(&(sg_buffer_desc){
+        .type = SG_BUFFERTYPE_STORAGEBUFFER,
+        .data = SG_RANGE(vertices),
+        .label = "cube-vertices",
+    });
+
+    // an index buffer with the cube indices
+    uint16_t indices[] = {
+        0, 1, 2,  0, 2, 3,
+        6, 5, 4,  7, 6, 4,
+        8, 9, 10,  8, 10, 11,
+        14, 13, 12,  15, 14, 12,
+        16, 17, 18,  16, 18, 19,
+        22, 21, 20,  23, 22, 20
+    };
+    state.bind.index_buffer = sg_make_buffer(&(sg_buffer_desc){
+        .type = SG_BUFFERTYPE_INDEXBUFFER,
+        .data = SG_RANGE(indices),
+        .label = "cube-indices",
+    });
+
+    // a storage buffer with a color palette
+    sb_color_t colors[] = {
+        { .color = { 1.0f, 0.0f, 0.0f, 1.0f } },
+        { .color = { 0.0f, 1.0f, 0.0f, 1.0f } },
+        { .color = { 0.0f, 0.0f, 1.0f, 1.0f } },
+        { .color = { 0.5f, 0.0f, 1.0f, 1.0f } },
+        { .color = { 0.0f, 0.5f, 1.0f, 1.0f } },
+        { .color = { 1.0f, 0.5f, 0.0f, 1.0f } },
+    };
+    state.bind.fs.storage_buffers[SLOT_colors] = sg_make_buffer(&(sg_buffer_desc){
+        .type = SG_BUFFERTYPE_STORAGEBUFFER,
+        .data = SG_RANGE(colors),
+        .label = "color-palette",
+    });
+
+    // a greyscale texture which modules the color palette colors
+    uint8_t pixels[4][4] = {
+        { 0xFF, 0xCC, 0x88, 0x44 },
+        { 0xCC, 0x88, 0x44, 0xFF },
+        { 0x88, 0x44, 0xFF, 0xCC },
+        { 0x44, 0xFF, 0xCC, 0x88 },
+    };
+    state.bind.fs.images[SLOT_tex] = sg_make_image(&(sg_image_desc){
+        .width = 4,
+        .height = 4,
+        .pixel_format = SG_PIXELFORMAT_R8,
+        .data.subimage[0][0] = SG_RANGE(pixels),
+        .label = "texture",
+    });
+
+    // ...and a matching sampler
+    state.bind.fs.samplers[SLOT_smp] = sg_make_sampler(&(sg_sampler_desc){
+        .min_filter = SG_FILTER_NEAREST,
+        .mag_filter = SG_FILTER_NEAREST,
+        .label = "sampler",
+    });
+
+    // ...shader and pipeline object (note: no vertex layout needed because
+    // the vertex shader pulls vertices from storage buffer)
+    state.pip = sg_make_pipeline(&(sg_pipeline_desc){
+        .shader = sg_make_shader(sbuftex_shader_desc(sg_query_backend())),
+        .index_type = SG_INDEXTYPE_UINT16,
+        .cull_mode = SG_CULLMODE_BACK,
+        .depth = {
+            .compare = SG_COMPAREFUNC_LESS_EQUAL,
+            .write_enabled = true,
+        },
+        .label = "pipeline",
+    });
+}
+
+static void frame(void) {
+    const vs_params_t vs_params = make_vs_params();
+    sg_begin_pass(&(sg_pass){ .action = state.pass_action, .swapchain = sglue_swapchain() });
+    if (sg_query_features().storage_buffer) {
+        sg_apply_pipeline(state.pip);
+        sg_apply_bindings(&state.bind);
+        sg_apply_uniforms(SG_SHADERSTAGE_VS, SLOT_vs_params, &SG_RANGE(vs_params));
+        sg_draw(0, 36, 1);
+    }
+    __dbgui_draw();
+    sg_end_pass();
+    sg_commit();
+}
+
+static vs_params_t make_vs_params(void) {
+    const float t = (float)(sapp_frame_duration() * 60.0);
+    hmm_mat4 proj = HMM_Perspective(60.0f, sapp_widthf()/sapp_heightf(), 0.01f, 10.0f);
+    hmm_mat4 view = HMM_LookAt(HMM_Vec3(0.0f, 1.5f, 6.0f), HMM_Vec3(0.0f, 0.0f, 0.0f), HMM_Vec3(0.0f, 1.0f, 0.0f));
+    hmm_mat4 view_proj = HMM_MultiplyMat4(proj, view);
+    state.rx += 1.0f * t; state.ry += 2.0f * t;
+    hmm_mat4 rxm = HMM_Rotate(state.rx, HMM_Vec3(1.0f, 0.0f, 0.0f));
+    hmm_mat4 rym = HMM_Rotate(state.ry, HMM_Vec3(0.0f, 1.0f, 0.0f));
+    hmm_mat4 model = HMM_MultiplyMat4(rxm, rym);
+    return (vs_params_t){ .mvp = HMM_MultiplyMat4(view_proj, model) };
+}
+
+static void cleanup(void) {
+    __dbgui_shutdown();
+    sg_shutdown();
+}
+
+sapp_desc sokol_main(int argc, char* argv[]) {
+    (void)argc; (void)argv;
+    return (sapp_desc){
+        .init_cb = init,
+        .frame_cb = frame,
+        .cleanup_cb = cleanup,
+        .event_cb = __dbgui_event,
+        .width = 800,
+        .height = 600,
+        .sample_count = 4,
+        .window_title = "sbuftex-sapp.c",
+        .icon.sokol_default = true,
+        .logger.func = slog_func,
+    };
+}

sapp/sbuftex-sapp.glsl

@@ -0,0 +1,48 @@
+@ctype mat4 hmm_mat4
+
+@vs vs
+uniform vs_params {
+    mat4 mvp;
+};
+
+struct sb_vertex {
+    vec3 pos;
+    uint idx;
+    vec2 uv;
+};
+
+readonly buffer vertices {
+    sb_vertex vtx[];
+};
+
+out vec3 uv_idx;
+
+void main() {
+    gl_Position = mvp * vec4(vtx[gl_VertexIndex].pos, 1.0);
+    uv_idx = vec3(vtx[gl_VertexIndex].uv, float(vtx[gl_VertexIndex].idx));
+}
+@end
+
+@fs fs
+uniform texture2D tex;
+uniform sampler smp;
+
+struct sb_color {
+    vec4 color;
+};
+
+readonly buffer colors {
+    sb_color clr[];
+};
+
+in vec3 uv_idx;
+out vec4 frag_color;
+
+void main() {
+    uint idx = uint(uv_idx.z);
+    vec2 uv = uv_idx.xy;
+    frag_color = vec4(texture(sampler2D(tex,smp), uv).xxx, 1.0) * clr[idx].color;
+}
+@end
+
+@program sbuftex vs fs