sokol.c

//------------------------------------------------------------------------------
//  triangle-emsc.c
//  Vertex buffer, simple shader, pipeline state object.
//------------------------------------------------------------------------------
#define SOKOL_IMPL
#define SOKOL_GLES2
#include "sokol_gfx.h"

sg_draw_state draw_state;

/* default pass action (clear to grey) */
sg_pass_action pass_action = {0};

float WIDTH = 600f;
float HEIGHT = 400f;

void initSokolHello() {
    /* setup sokol_gfx */
    sg_desc desc = {0};
    sg_setup(&desc);
    assert(sg_isvalid());

    /* a vertex buffer with 3 vertices */
    float vertices[] = {
        // positions            // colors
        0.0f, 0.5f, 0.5f, 1.0f, 0.0f, 0.0f, 1.0f,
        0.5f, -0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 1.0f,
        -0.5f, -0.5f, 0.5f, 0.0f, 0.0f, 1.0f, 1.0f
    };
    sg_buffer_desc buf_desc = {
        .size = sizeof(vertices),
        .data_ptr = vertices,
        .data_size = sizeof(vertices)
    };

    /* create a shader */
    sg_shader_desc shd_desc = {
        .vs.source =
            "attribute vec4 position;\n"
            "attribute vec4 color0;\n"
            "varying vec4 color;\n"
            "void main() {\n"
            "  gl_Position = position;\n"
            "  color = color0;\n"
            "}\n",
        .fs.source =
            "precision mediump float;\n"
            "varying vec4 color;\n"
            "void main() {\n"
            "  gl_FragColor = color;\n"
            "}\n"
    };

    /* create a pipeline object (default render states are fine for triangle) */
    sg_pipeline_desc pip_desc = {
        .vertex_layouts[0] = {
            .stride = 28,
            .attrs = {
                    [0] = {.name = "position", .offset = 0, .format = SG_VERTEXFORMAT_FLOAT3},
                    [1] = {.name = "color0", .offset = 12, .format = SG_VERTEXFORMAT_FLOAT4}}},
        .shader = sg_make_shader(&shd_desc),
    };

    /* setup the draw state with resource bindings */
    draw_state = (sg_draw_state){
        .pipeline = sg_make_pipeline(&pip_desc),
        .vertex_buffers[0] = sg_make_buffer(&buf_desc)
    };
}

/* draw one frame */
void drawSokolHelloWorld() {
    sg_begin_default_pass(&pass_action, WIDTH, HEIGHT);
    sg_apply_draw_state(&draw_state);
    sg_draw(0, 3, 1);
    sg_end_pass();
    sg_commit();
}

void endSokolHelloWorld() {
    sg_shutdown();
}

void ctoy_begin() {
    initSokolHello();
}

void ctoy_end() {
    endSokolHelloWorld();
}

void ctoy_main_loop() {
    drawSokolHelloWorld();
}