examples: add render-pass-ext exmaple

examples/render-pass-ext/gles2/triangle_pass.c

@@ -0,0 +1,135 @@
+#include <stdbool.h>
+#include <stdlib.h>
+#include <wlr/render/gles2.h>
+#include <wlr/util/log.h>
+#include <render/gles2.h>
+
+#include "triangle_pass.h"
+
+#include "triangle_vert.h"
+#include "triangle_frag.h"
+
+static void custom_triangle_render(struct wlr_render_pass *render_pass,
+		const struct custom_render_triangle_options *options) {
+	struct wlr_gles2_render_pass *wlr_gles2_pass =
+		wlr_gles2_render_pass_from_render_pass(render_pass);
+	struct render_triangle_pass *base =
+		wlr_gles2_pass->buffer->renderer->wlr_renderer.data;
+	struct gles2_render_triangle_pass *triangle_pass =
+		gles2_render_triangle_pass_from_pass(base);
+	struct wlr_gles2_renderer *renderer = wlr_gles2_pass->buffer->renderer;
+
+	struct wlr_box box;
+	struct wlr_buffer *wlr_buffer = wlr_gles2_pass->buffer->buffer;
+	custom_render_triangle_options_get_box(options, wlr_buffer, &box);
+
+	int width = wlr_gles2_pass->buffer->buffer->width;
+	int height = wlr_gles2_pass->buffer->buffer->height;
+
+	float x0 = options->box.x + options->box.width * 0.50f;
+	float y0 = options->box.y + options->box.height * 0.10f;
+	float x1 = options->box.x + options->box.width * 0.10f;
+	float y1 = options->box.y + options->box.height * 0.90f;
+	float x2 = options->box.x + options->box.width * 0.90f;
+	float y2 = options->box.y + options->box.height * 0.90f;
+
+	GLfloat verts[3][5] = {
+		{ x0 / width * 2.0f - 1.0f, 1.0f - y0 / height * 2.0f, 1.0f, 0.1f, 0.1f },
+		{ x1 / width * 2.0f - 1.0f, 1.0f - y1 / height * 2.0f, 0.1f, 1.0f, 0.1f },
+		{ x2 / width * 2.0f - 1.0f, 1.0f - y2 / height * 2.0f, 0.1f, 0.2f, 1.0f },
+	};
+
+	wlr_gles2_push_debug(renderer);
+	glDisable(GL_SCISSOR_TEST);
+	glDisable(GL_BLEND);
+
+	glUseProgram(triangle_pass->shader.program);
+	wlr_gles_set_proj_matrix(triangle_pass->shader.proj, wlr_gles2_pass->projection_matrix, &box);
+	glEnableVertexAttribArray(triangle_pass->shader.pos_attrib);
+	glVertexAttribPointer(triangle_pass->shader.pos_attrib, 2, GL_FLOAT, GL_FALSE,
+		5 * sizeof(GLfloat), verts);
+	glEnableVertexAttribArray(triangle_pass->shader.color_attrib);
+	glVertexAttribPointer(triangle_pass->shader.color_attrib, 3, GL_FLOAT, GL_FALSE,
+		5 * sizeof(GLfloat), &verts[0][2]);
+
+	glDrawArrays(GL_TRIANGLES, 0, 3);
+
+	glDisableVertexAttribArray(triangle_pass->shader.pos_attrib);
+	glDisableVertexAttribArray(triangle_pass->shader.color_attrib);
+	wlr_gles2_pop_debug(renderer);
+}
+
+static void custom_triangle_destroy(struct render_triangle_pass *pass) {
+	struct gles2_render_triangle_pass *gles2_pass =
+		gles2_render_triangle_pass_from_pass(pass);
+	if (gles2_pass->shader.program != 0) {
+		glDeleteProgram(gles2_pass->shader.program);
+	}
+
+	free(gles2_pass);
+}
+
+static const struct render_triangle_pass_impl custom_triangle_impl = {
+	.destroy = custom_triangle_destroy,
+	.render = custom_triangle_render,
+};
+
+struct render_triangle_pass *gles2_render_triangle_pass_create(
+		struct wlr_renderer *wlr_renderer) {
+	struct gles2_render_triangle_pass *pass = calloc(1, sizeof(*pass));
+	if (pass == NULL) {
+		wlr_log_errno(WLR_ERROR, "failed to allocate gles2_render_triangle_pass");
+		return NULL;
+	}
+
+	struct wlr_gles2_renderer *renderer =  wlr_gles2_renderer_from_renderer(wlr_renderer);
+	if (!wlr_egl_make_current(renderer->egl, NULL)) {
+		free(pass);
+		return NULL;
+	}
+
+	render_triangle_pass_init(&pass->base, &custom_triangle_impl);
+	wlr_gles2_push_debug(renderer);
+	GLuint prog;
+	pass->shader.program = prog =
+		wlr_gles2_link_program(renderer, custom_triangle_vert, custom_triangle_frag);
+	if (!pass->shader.program) {
+		goto error;
+	}
+
+	pass->shader.proj = -1;
+	pass->shader.color_attrib = glGetAttribLocation(pass->shader.program, "color");
+	pass->shader.pos_attrib = glGetAttribLocation(pass->shader.program, "pos");
+	if (pass->shader.pos_attrib < 0 || pass->shader.color_attrib < 0) {
+		wlr_log(WLR_ERROR, "triangle shader attribute lookup failed: pos=%d color=%d",
+			pass->shader.pos_attrib, pass->shader.color_attrib);
+		goto error;
+	}
+	wlr_gles2_pop_debug(renderer);
+	wlr_egl_unset_current(renderer->egl);
+	pass->renderer = renderer;
+	return &pass->base;
+
+error:
+	render_triangle_pass_destroy(&pass->base);
+	wlr_gles2_pop_debug(renderer);
+	wlr_egl_unset_current(renderer->egl);
+
+	return NULL;
+}
+
+bool render_triangle_pass_is_gles2(const struct render_triangle_pass *triangle_pass) {
+	return triangle_pass->impl == & custom_triangle_impl;
+}
+
+struct gles2_render_triangle_pass *gles2_render_triangle_pass_from_pass(
+		struct render_triangle_pass *triangle_pass) {
+	if (!render_triangle_pass_is_gles2(triangle_pass)) {
+		return NULL;
+	}
+
+	struct gles2_render_triangle_pass *gles2_pass =
+		wl_container_of(triangle_pass, gles2_pass, base);
+
+	return gles2_pass;
+}