Switch to GLES2

Closes #13

4 files changed, 347 insertions, 0 deletions

diff --git a/render/gles2/renderer.c b/render/gles2/renderer.c
new file mode 100644
index 00000000..07647f2f
--- /dev/null
+++ b/render/gles2/renderer.c
@@ -0,0 +1,183 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <GLES2/gl2.h>
+#include <wayland-util.h>
+#include <wayland-server-protocol.h>
+#include <wlr/render.h>
+#include <wlr/render/interface.h>
+#include <wlr/render/matrix.h>
+#include <wlr/util/log.h>
+#include "render/gles2.h"
+
+static struct {
+	bool initialized;
+	GLuint rgb, rgba;
+	GLuint quad;
+	GLuint ellipse;
+} shaders;
+
+static bool compile_shader(GLuint type, const GLchar *src, GLuint *shader) {
+	*shader = GL_CALL(glCreateShader(type));
+	int len = strlen(src);
+	GL_CALL(glShaderSource(*shader, 1, &src, &len));
+	GL_CALL(glCompileShader(*shader));
+	GLint success;
+	GL_CALL(glGetShaderiv(*shader, GL_COMPILE_STATUS, &success));
+	if (success == GL_FALSE) {
+		GLint loglen;
+		GL_CALL(glGetShaderiv(*shader, GL_INFO_LOG_LENGTH, &loglen));
+		GLchar msg[loglen];
+		GL_CALL(glGetShaderInfoLog(*shader, loglen, &loglen, msg));
+		wlr_log(L_ERROR, "Shader compilation failed");
+		wlr_log(L_ERROR, "%s", msg);
+		exit(1);
+		return false;
+	}
+	return true;
+}
+
+static bool compile_program(const GLchar *vert_src,
+		const GLchar *frag_src, GLuint *program) {
+	GLuint vertex, fragment;
+	if (!compile_shader(GL_VERTEX_SHADER, vert_src, &vertex)) {
+		return false;
+	}
+	if (!compile_shader(GL_FRAGMENT_SHADER, frag_src, &fragment)) {
+		glDeleteProgram(vertex);
+		return false;
+	}
+	*program = GL_CALL(glCreateProgram());
+	GL_CALL(glAttachShader(*program, vertex));
+	GL_CALL(glAttachShader(*program, fragment));
+	GL_CALL(glLinkProgram(*program));
+	return true;
+}
+
+static void init_default_shaders() {
+	if (shaders.initialized) {
+		return;
+	}
+	if (!compile_program(vertex_src, fragment_src_RGB, &shaders.rgb)) {
+		goto error;
+	}
+	if (!compile_program(vertex_src, fragment_src_RGBA, &shaders.rgba)) {
+		goto error;
+	}
+	if (!compile_program(quad_vertex_src, quad_fragment_src, &shaders.quad)) {
+		goto error;
+	}
+	if (!compile_program(quad_vertex_src, ellipse_fragment_src, &shaders.ellipse)) {
+		goto error;
+	}
+	wlr_log(L_DEBUG, "Compiled default shaders");
+	return;
+error:
+	wlr_log(L_ERROR, "Failed to set up default shaders!");
+}
+
+static void init_globals() {
+	init_default_shaders();
+}
+
+static void wlr_gles2_begin(struct wlr_renderer_state *state,
+		struct wlr_output *output) {
+	// TODO: let users customize the clear color?
+	GL_CALL(glClearColor(0.25f, 0.25f, 0.25f, 1));
+	GL_CALL(glClear(GL_COLOR_BUFFER_BIT));
+	int32_t width = output->width;
+	int32_t height = output->height;
+	GL_CALL(glViewport(0, 0, width, height));
+	// Note: maybe we should save output projection and remove some of the need
+	// for users to sling matricies themselves
+}
+
+static void wlr_gles2_end(struct wlr_renderer_state *state) {
+	// no-op
+}
+
+static struct wlr_surface *wlr_gles2_surface_init(struct wlr_renderer_state *state) {
+	return gles2_surface_init();
+}
+
+static void draw_quad() {
+	GLfloat verts[] = {
+		1, 0, // top right
+		0, 0, // top left
+		1, 1, // bottom right
+		0, 1, // bottom left
+	};
+	GLfloat texcoord[] = {
+		1, 0, // top right
+		0, 0, // top left
+		1, 1, // bottom right
+		0, 1, // bottom left
+	};
+
+	GL_CALL(glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, verts));
+	GL_CALL(glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, texcoord));
+
+	GL_CALL(glEnableVertexAttribArray(0));
+	GL_CALL(glEnableVertexAttribArray(1));
+
+	GL_CALL(glDrawArrays(GL_TRIANGLE_STRIP, 0, 4));
+
+	GL_CALL(glDisableVertexAttribArray(0));
+	GL_CALL(glDisableVertexAttribArray(1));
+}
+
+static bool wlr_gles2_render_surface(struct wlr_renderer_state *state,
+		struct wlr_surface *surface, const float (*matrix)[16]) {
+	assert(surface && surface->valid);
+	switch (surface->format) {
+	case GL_RGB:
+		GL_CALL(glUseProgram(shaders.rgb));
+		break;
+	case GL_RGBA:
+		GL_CALL(glUseProgram(shaders.rgba));
+		break;
+	default:
+		wlr_log(L_ERROR, "No shader for this surface format");
+		return false;
+	}
+	gles2_flush_errors();
+	wlr_surface_bind(surface);
+	GL_CALL(glUniformMatrix4fv(0, 1, GL_TRUE, *matrix));
+	draw_quad();
+	return true;
+}
+
+static void wlr_gles2_render_quad(struct wlr_renderer_state *state,
+		const float (*color)[4], const float (*matrix)[16]) {
+	GL_CALL(glUseProgram(shaders.quad));
+	GL_CALL(glUniformMatrix4fv(0, 1, GL_TRUE, *matrix));
+	GL_CALL(glUniform4f(1, (*color)[0], (*color)[1], (*color)[2], (*color)[3]));
+	draw_quad();
+}
+
+static void wlr_gles2_render_ellipse(struct wlr_renderer_state *state,
+		const float (*color)[4], const float (*matrix)[16]) {
+	GL_CALL(glUseProgram(shaders.ellipse));
+	GL_CALL(glUniformMatrix4fv(0, 1, GL_TRUE, *matrix));
+	GL_CALL(glUniform4f(1, (*color)[0], (*color)[1], (*color)[2], (*color)[3]));
+	draw_quad();
+}
+
+static void wlr_gles2_destroy(struct wlr_renderer_state *state) {
+	// no-op
+}
+
+static struct wlr_renderer_impl wlr_renderer_impl = {
+	.begin = wlr_gles2_begin,
+	.end = wlr_gles2_end,
+	.surface_init = wlr_gles2_surface_init,
+	.render_with_matrix = wlr_gles2_render_surface,
+	.render_quad = wlr_gles2_render_quad,
+	.render_ellipse = wlr_gles2_render_ellipse,
+	.destroy = wlr_gles2_destroy
+};
+
+struct wlr_renderer *wlr_gles2_renderer_init() {
+	init_globals();
+	return wlr_renderer_init(NULL, &wlr_renderer_impl);
+}
diff --git a/render/gles2/shaders.c b/render/gles2/shaders.c
new file mode 100644
index 00000000..850c0618
--- /dev/null
+++ b/render/gles2/shaders.c
@@ -0,0 +1,63 @@
+#include "render/gles2.h"
+#include <GLES2/gl2.h>
+
+// Colored quads
+const GLchar quad_vertex_src[] =
+"uniform mat4 proj;"
+"uniform vec4 color;"
+"attribute vec2 pos;"
+"attribute vec2 texcoord;"
+"varying vec4 v_color;"
+"varying vec2 v_texcoord;"
+"void main() {"
+"  gl_Position = proj * vec4(pos, 0.0, 1.0);"
+"  v_color = color;"
+"  v_texcoord = texcoord;"
+"}";
+
+const GLchar quad_fragment_src[] =
+"precision mediump float;"
+"varying vec4 v_color;"
+"varying vec2 v_texcoord;"
+"void main() {"
+"  gl_FragColor = v_color;"
+"}";
+
+// Colored ellipses (TODO)
+
+const GLchar ellipse_fragment_src[] =
+"precision mediump float;"
+"varying vec4 v_color;"
+"varying vec2 v_texcoord;"
+"void main() {"
+"  float l = length(v_texcoord - vec2(0.5, 0.5));"
+"  if (l > 0.5) discard;"
+"  gl_FragColor = v_color;"
+"}";
+
+// Textured quads
+const GLchar vertex_src[] =
+"uniform mat4 proj;"
+"attribute vec2 pos;"
+"attribute vec2 texcoord;"
+"varying vec2 v_texcoord;"
+"void main() {"
+"	gl_Position = proj * vec4(pos, 0.0, 1.0);"
+"	v_texcoord = texcoord;"
+"}";
+
+const GLchar fragment_src_RGB[] =
+"precision mediump float;"
+"varying vec2 v_texcoord;"
+"uniform sampler2D tex;"
+"void main() {"
+"	gl_FragColor = vec4(texture2D(tex, v_texcoord).rgb, 1.0);"
+"}";
+
+const GLchar fragment_src_RGBA[] =
+"precision mediump float;"
+"varying vec2 v_texcoord;"
+"uniform sampler2D tex;"
+"void main() {"
+"	gl_FragColor = texture2D(tex, v_texcoord);"
+"}";
diff --git a/render/gles2/surface.c b/render/gles2/surface.c
new file mode 100644
index 00000000..278b3dc3
--- /dev/null
+++ b/render/gles2/surface.c
@@ -0,0 +1,63 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <GLES2/gl2.h>
+#include <wayland-util.h>
+#include <wayland-server-protocol.h>
+#include <wlr/render.h>
+#include <wlr/render/interface.h>
+#include <wlr/render/matrix.h>
+#include "render/gles2.h"
+
+static bool gles2_surface_attach_pixels(struct wlr_surface_state *surface,
+		uint32_t format, int width, int height, const unsigned char *pixels) {
+	assert(surface);
+	surface->wlr_surface->width = width;
+	surface->wlr_surface->height = height;
+	surface->wlr_surface->format = format;
+	GL_CALL(glGenTextures(1, &surface->tex_id));
+	GL_CALL(glBindTexture(GL_TEXTURE_2D, surface->tex_id));
+	GL_CALL(glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0,
+			format, GL_UNSIGNED_BYTE, pixels));
+	surface->wlr_surface->valid = true;
+	return true;
+}
+
+static void gles2_surface_get_matrix(struct wlr_surface_state *surface,
+		float (*matrix)[16], const float (*projection)[16], int x, int y) {
+	struct wlr_surface *_surface = surface->wlr_surface;
+	float world[16];
+	wlr_matrix_identity(matrix);
+	wlr_matrix_translate(&world, x, y, 0);
+	wlr_matrix_mul(matrix, &world, matrix);
+	wlr_matrix_scale(&world, _surface->width, _surface->height, 1);
+	wlr_matrix_mul(matrix, &world, matrix);
+	wlr_matrix_mul(projection, matrix, matrix);
+}
+
+static void gles2_surface_bind(struct wlr_surface_state *surface) {
+	GL_CALL(glActiveTexture(GL_TEXTURE0 + 1));
+	GL_CALL(glBindTexture(GL_TEXTURE_2D, surface->tex_id));
+	GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR));
+	GL_CALL(glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR));
+}
+
+static void gles2_surface_destroy(struct wlr_surface_state *surface) {
+	GL_CALL(glDeleteTextures(1, &surface->tex_id));
+	free(surface);
+}
+
+static struct wlr_surface_impl wlr_surface_impl = {
+	.attach_pixels = gles2_surface_attach_pixels,
+	// .attach_shm = TODO
+	.get_matrix = gles2_surface_get_matrix,
+	.bind = gles2_surface_bind,
+	.destroy = gles2_surface_destroy,
+};
+
+struct wlr_surface *gles2_surface_init() {
+	struct wlr_surface_state *state = calloc(sizeof(struct wlr_surface_state), 1);
+	struct wlr_surface *surface = wlr_surface_init(state, &wlr_surface_impl);
+	state->wlr_surface = surface;
+	return surface;
+}
diff --git a/render/gles2/util.c b/render/gles2/util.c
new file mode 100644
index 00000000..9498a1cd
--- /dev/null
+++ b/render/gles2/util.c
@@ -0,0 +1,38 @@
+#include <stdlib.h>
+#include <stdbool.h>
+#include <GLES2/gl2.h>
+#include <wlr/util/log.h>
+#include "render/gles2.h"
+
+const char *gles2_strerror(GLenum err) {
+	switch (err) {
+	case GL_INVALID_ENUM:
+		return "Invalid enum";
+	case GL_INVALID_VALUE:
+		return "Invalid value";
+	case GL_INVALID_OPERATION:
+		return "Invalid operation";
+	case GL_OUT_OF_MEMORY:
+		return "Out of memory";
+	case GL_INVALID_FRAMEBUFFER_OPERATION:
+		return "Invalid framebuffer operation";
+	default:
+		return "Unknown error";
+	}
+}
+
+bool _gles2_flush_errors(const char *file, int line) {
+	GLenum err;
+	bool failure = false;
+	while ((err = glGetError()) != GL_NO_ERROR) {
+		failure = true;
+		if (err == GL_OUT_OF_MEMORY) {
+			// The OpenGL context is now undefined
+			_wlr_log(L_ERROR, "[%s:%d] Fatal GL error: out of memory", file, line);
+			exit(1);
+		} else {
+			_wlr_log(L_ERROR, "[%s:%d] GL error %d %s", file, line, err, gles2_strerror(err));
+		}
+	}
+	return failure;
+}