/**
Uses glReadPixels to read the bytes of the given context's drawing buffer into
an unsigned char array
@param ctx the given context2d
@return an unsigned char array containing the bytes of ctx's draw buffer
**/
unsigned char *context_2d_read_pixels(context_2d *ctx) {
//must flush before reading as canvas may not be ready
//to be read from
draw_textures_flush();
unsigned char *buffer = NULL;
buffer = (unsigned char *)malloc(sizeof(unsigned char) * 4 * ctx->width * ctx->height);
glReadPixels(0, 0, ctx->width, ctx->height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
return buffer;
}
/**
* @name context_2d_draw_point_sprites
* @brief Draws pointsprites using the given options (in batch along a line)
* @param ctx - (context_2d *) context to draw to
* @param url - (const char *) name of the texture to draw from
* @param point_size - (float) point sprite size
* @param step_size - (float) step size to take between drawn pointsprites
* @param color - (rgba *) color to draw with
* @param x1 - (float) starting x-coordinate to draw along
* @param y1 - (float) starting y-coordinate to draw along
* @param x2 - (float) ending x-coordinate to draw along
* @param y2 - (float) ending y-coordinate to draw along
* @retval NONE
*/
void context_2d_draw_point_sprites(context_2d *ctx, const char *url, float point_size, float step_size, rgba *color, float x1, float y1, float x2, float y2) {
draw_textures_flush();
context_2d_bind(ctx);
texture_2d *tex = texture_manager_load_texture(texture_manager_get(), url);
// If texture is not finished loading,
if (!tex || !tex->loaded) {
return;
}
static GLfloat *vertex_buffer = NULL;
static unsigned int vertex_max = 64;
tealeaf_shaders_bind(DRAWING_SHADER);
matrix_3x3_multiply_m_f_f_f_f(GET_MODEL_VIEW_MATRIX(ctx), x1, y1, &x1, &y1);
matrix_3x3_multiply_m_f_f_f_f(GET_MODEL_VIEW_MATRIX(ctx), x2, y2, &x2, &y2);
// Allocate vertex array buffer
if (vertex_buffer == NULL) {
vertex_buffer = malloc(vertex_max * 2 * sizeof(GLfloat));
}
// Add points to the buffer so there are drawing points every X pixels
unsigned int count = ceilf(sqrtf((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1)) / step_size);
if (count < 1) {
count = 1;
}
unsigned int vertex_count = 0;
unsigned int i;
for (i = 0; i < count; ++i) {
if (vertex_count == vertex_max) {
vertex_max = 2 * vertex_max;
vertex_buffer = realloc(vertex_buffer, vertex_max * 2 * sizeof(GLfloat));
}
vertex_buffer[2 * vertex_count + 0] = x1 + (x2 - x1) * ((GLfloat)i / (GLfloat)count);
vertex_buffer[2 * vertex_count + 1] = y1 + (y2 - y1) * ((GLfloat)i / (GLfloat)count);
vertex_count += 1;
}
GLTRACE(glActiveTexture(GL_TEXTURE0));
GLTRACE(glBindTexture(GL_TEXTURE_2D, tex->name));
GLTRACE(glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA));
GLTRACE(glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
GLTRACE(glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
GLTRACE(glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE));
GLTRACE(glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE));
// Render the vertex array
GLTRACE(glUniform1f(global_shaders[DRAWING_SHADER].point_size, point_size));
GLTRACE(glVertexAttribPointer(global_shaders[DRAWING_SHADER].vertex_coords, 2, GL_FLOAT, GL_FALSE, 0, (float *) vertex_buffer));
float alpha = color->a * ctx->globalAlpha[ctx->mvp];
GLTRACE(glUniform4f(global_shaders[DRAWING_SHADER].draw_color, alpha * color->r, alpha * color->g, alpha * color->b, alpha));
GLTRACE(glDrawArrays(GL_POINTS, 0, vertex_count));
tealeaf_shaders_bind(PRIMARY_SHADER);
}
/**
* @name enable_scissor
* @brief enables the use of glScissors using proprties from the given context
* @param ctx - (context_2d *)
* @retval NONE
*/
void enable_scissor(context_2d *ctx) {
rect_2d *bounds = GET_CLIPPING_BOUNDS(ctx);
if (rect_2d_equals(&last_scissor_rect, bounds)) {
return;
}
draw_textures_flush();
last_scissor_rect.x = bounds->x;
last_scissor_rect.y = bounds->y;
last_scissor_rect.width = bounds->width;
last_scissor_rect.height = bounds->height;
GLTRACE(glScissor((int) bounds->x, (int) bounds->y, (int) bounds->width, (int) bounds->height));
GLTRACE(glEnable(GL_SCISSOR_TEST));
}
/**
* @name context_2d_clearRect
* @brief clears the given rect on the given context
* @param ctx - (context_2d *) context to clear a rect from
* @param rect - (const rect_2d *) rect to clear from the context
* @retval NONE
*/
void context_2d_clearRect(context_2d *ctx, const rect_2d *rect) {
draw_textures_flush();
context_2d_bind(ctx);
// Draw a rectangle using triangle strip:
// (0,1)-(2,3)-(4,5) and (2,3)-(4,5)-(6,7)
//
// With coordinates:
// 4,5 - 6,7
// | \ |
// 0,1 - 2,3
GLfloat v[8];
matrix_3x3_multiply(GET_MODEL_VIEW_MATRIX(ctx), rect, (float *)&v[4], (float *)&v[5], (float *)&v[6], (float *)&v[7], (float *)&v[2], (float *)&v[3], (float *)&v[0], (float *)&v[1]);
glBlendFunc(GL_ONE, GL_ZERO);
glUniform4f(global_shaders[PRIMARY_SHADER].draw_color, 0, 0, 0, 0); // set color to 0
glVertexAttribPointer(global_shaders[PRIMARY_SHADER].vertex_coords, 2, GL_FLOAT, GL_FALSE, 0, v);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
}
/**
* @name context_2d_fillRect
* @brief fills a rectangle on the given context using given options
* @param ctx - (context_2d *) context to fill a rectangle on
* @param rect - (const rect_2d *) rect to be filled
* @param color - (const rgba *) color to fill with
* @param composite_op - deprecated
* @retval NONE
*/
void context_2d_fillRect(context_2d *ctx, const rect_2d *rect, const rgba *color) {
if (use_single_shader) {
return;
}
draw_textures_flush();
context_2d_bind(ctx);
tealeaf_shaders_bind(FILL_RECT_SHADER);
apply_composite_operation(ctx->globalCompositeOperation[ctx->mvp]);
rect_2d_vertices in, out;
rect_2d_to_rect_2d_vertices(rect, &in);
matrix_3x3_multiply_m_r_r(GET_MODEL_VIEW_MATRIX(ctx), &in, &out);
float alpha = color->a * ctx->globalAlpha[ctx->mvp];
// TODO: will pre-multiplied alpha cause a loss-of-precision in color for filling rectangles?
GLTRACE(glUniform4f(global_shaders[FILL_RECT_SHADER].draw_color, alpha * color->r, alpha * color->g, alpha * color->b, alpha));
GLTRACE(glVertexAttribPointer(global_shaders[FILL_RECT_SHADER].vertex_coords, 2, GL_FLOAT, GL_FALSE, 0, &out));
GLTRACE(glDrawArrays(GL_TRIANGLE_STRIP, 0, 4));
tealeaf_shaders_bind(PRIMARY_SHADER);
}
/**
* @name tealeaf_canvas_context_2d_bind
* @brief uses the given texture to bind to either the render buffer or a fbo
* @param ctx - (context_2d *) pointer to the context to use for binding
* @retval bool - whether the bind failed or succeeded
*/
bool tealeaf_canvas_context_2d_bind(context_2d *ctx) {
if (canvas.active_ctx != ctx) {
draw_textures_flush();
// Update active context after flushing
canvas.active_ctx = ctx;
if (ctx->on_screen) {
tealeaf_canvas_bind_render_buffer(ctx);
} else {
tealeaf_canvas_bind_texture_buffer(ctx);
}
tealeaf_context_update_viewport(ctx, false);
if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
LOG("{canvas} WARNING: Failed to make complete framebuffer %i", glCheckFramebufferStatus(GL_FRAMEBUFFER));
}
return true;
} else {
return false;
}
}
/**
* @name context_2d_flush
* @brief flushes the texture drawing queue
* @param ctx - deprecated
* @retval NONE
*/
void context_2d_flush(context_2d *ctx) {
draw_textures_flush();
}
/**
* @name context_2d_clear
* @brief
* @param ctx - (context_2d *)
* @retval NONE
*/
void context_2d_clear(context_2d *ctx) {
draw_textures_flush();
context_2d_bind(ctx);
glClearColor(0, 0, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);
}
/**
* @name disable_scissor
* @brief disables the use of glScissors
* @param ctx - deprecated
* @retval NONE
*/
void disable_scissor(context_2d *ctx) {
draw_textures_flush();
last_scissor_rect.x = last_scissor_rect.y = 0;
last_scissor_rect.width = last_scissor_rect.height = -1;
GLTRACE(glDisable(GL_SCISSOR_TEST));
}
